Improvement in rock-drilling machines



R. BRYDUN, 1. s. oAvlosoN a T. s. wAnRlN ET UN.

Rock-Drilling Machines.-

Patented March 24 1874.

NOA/18,924.

lilllllllil muummmuul 'r nrrnn Sa'rn ROBERT BRYDON AND JAMES S.DAVIDSON, OF WHITEHAVEN, AND THOMAS A. WARRINGTON, OF LEWISHAM, GREATBRITAIN.

IMPROVEMENT IN ROCK-DRILLING MACHINES.

Specification forming part of Letters Patent No. 148,924, dated March24, 1874; application filed December 3l, 1873.

To all whom it may concern:

Be it known that we, ROBERT BRYDON and J Arms S. DAVIDSON, ofWhitehaven, in the county of Cumberland, England, and THOMAS A.IVARRINGTON, of Lewisham7 in the county of Kent, England, have inventedcertain Improvements in Rock-Drillin g Machines, of which the followingis a specification:

Our invention relates to certain improve ments, fully describedhereafter, in that class of rock-drilling machines in which the cuttingor boring tool or drill is attached to and actuated by a reciprocatingpiston-rod, the object of our invention being to render such machinesmore simple and efficient in construction and operation, and less liableto derangenient than usual.

In the accompanying drawing, Figure 1 is a longitudinal section of arock-drilling machine with our improvements; Fig. 2, a transversesection of a portion ofthe machine on the line A B, Fig. l Fig. 3, anend elevation; Fig. 4, a detached sectional view drawn to an enlargedscale; Figs. 5 and 6, longitudinal and transverse sections of a modifiedform of machine; Fig. 7, a sectional plan of part of the base or tripodon which the machine is supported; Fig. S, a detached view of part ofsaid base; and Fig. 9, a sectional elevation on the line E F, Fig. 7

The interior of the steam-cylinder, shown in Fig. l, instead of being ofuniform diameter throughout, as usual, is of greater diameter at the enda', which is lowermost, when the machine is in working position, than atits upper end a, and to these two portions of the cylinder are adaptedcorresponding pistons b and bl, both attached to the piston-rod c, tothe end c1 of which the cutting tool or drill is secured in the usualmanner. Our object in thus constructing the cylinders of two diiferentdiameters is to permit the tool to be drawn back quickly on the returnstroke, and to compensate for the loss of piston area due to thepresence of the piston-rod. d is the steam-chest, within which slidesthe valve e. W'e dispense entirely with the usual external valve-rods,stuffing-boxes, &c., and actuate the valve e from within the cylinderthrough the medium of a lever, f, having its fulcrum at f1, and formedwith branches f2 and f3, as shown, which are struck alternately by thetwo pistons, in order to operate said lever and valve. As shown in Fig.l, the return stroke has commenced, the enlarged lower end a of thecylinder being open to the steam, and the reduced upper end a being opento the exhaust. The valve c will remain in the position shown until thearm f3 of its lever f is struck and turned by the inner face of theadvancing piston b1, when the said valve will be reversed or movedsufficiently to open 'the upper end a of the'cylinder to the steam, andthe lower end a to the exhaust, and so on alternately. The face b2 ofthe piston b1 has ratchet-teeth formed upon it, with which the point f3of the lever f engages, and thus, owing to the curvilinear movement ofsaid lever, causes the piston, and consequently the piston-rod anddrill, to be turned in the direction of the arrow, Fig. l, during theirrearward movement. We prevent the accidental rotation of the piston-rod`and drill during the forward stroke by means of a bolt, g, beveled atone edge, and forced against the longitudinally grooved or channeled portion c ofthe piston-rod by a spiral spring, h, contained in a tube, t',which is screwed into the cylinder between the two pistons, as shown inFigs. 2. and 4. The beveled end of the spring-bolt enters one of thelongitudinal grooves of the piston-rod and eftectually prevents itsaccidental rotation during the forward stroke without interfering withits positive rotation by the lever f during the rear ward stroke. Wedispense with the usual external stuffing-box in the cylinder-head forthe passage of the piston-rod, and substitute in place of the same thearrangement shown in` Figs. l and 5, which consists of packingmaterialc, introduced into an internal recess on the inner side of thecylinder-head, and retained therein by aperforated washer or ring, z',which permits free access of the steam to the packing. Two parallelscrew-rods, l and l', are attached to lugs k k at the opposite ends ofthe exterior of the cylinder, and each passes through two brackets, mm', of a casing or jacket, o, which partially surrounds the cylinder,and which so 2 Maese guides and supports the latter as to permit it tobe longitudinally adjusted thereon, for the purpose of feeding orwithdrawing the drill. (See Figs. l and 3.) Each screw-rod is adapted toa Correspondingly-threaded nut, a, retained between the brackets m m ofthe jacket, and the said nuts hL ve Worm-teeth cut upon their exteriorcurved surfaces into which gear worms q and g on a transverse shaft, p,adapted to bearings on the jacket, and provided with an operating handleor handles, by turning` which both nuts n may be operated simultaneouslyand in either direction, as the cylinder and the tool carried by thesame are to be advanced or retracted. The jacket 0 is connected to thebase or main supporting frame X of the machine by a universal joint,which permits the said jacket to be adjusted to and retained at anyrequired position or angle.

The construction of this joint is as follows: A boss, r, Figs l and 3,turns on a horizontal bar, a, carried by the stand X, and to this bossis attached a headed pivot, r1, slotted, as shown, so as to receive aWedge, s. A loose bearing-plate, t, is interposed between the bar u andthe Wedge, and when the latter is tightened up by its nut s', the jacket0 will be prevented from turning on the pivot r1 by being tightlyclamped between. the head r2 of the said pivot and the wedge, and theboss 9 will, in like manner, be prevented from turning on the bar u bythe plate t, which Will be forced tightly against said bar by the Wedge.

The base or stand X (see Figs. 7, 8, and 9) has three legs, v o and x,the tivo former of which are enlarged at their upper ends to formcheek-pieces, through slots in which pass the forked ends of the leg,The cheek-pieces have projections o on their inner sides, to Which areadapted corresponding notches in the opposite ends of the tubular bar u,and the Whole of said parts is rigidly secured together by abinding-screw, g/,Yas best observed in Fig. 7.

The portion of our invention Which relates to the operation of theslide-valve from Within the cylinder, thereby dispensing with externalappliances, is applicable to sin gie-piston cylinders of an uniformdiameter throughout, as Well as to those having two pistons; but in suchcase it is necessary to employ two levers, f, as shown in themodification of Figs. 5 and 6-one to operate the valve When the pistonhas reached the limit of its movement in one direction, and the otherwhen it has reached the limit of its movement in the opposite direction.

We claim as our inventionl. In a rock-drilling machine, a piston, b1,adjoining the drill-rod, a smaller piston, b, and a rod connecting thetwo pistons, in combination with a cylinder common to both pistons, allas set forth.

2. The combination of the lever f With a piston having ratchet-teeth b2,adapted to the pointed end of said lever, as set forth, for the purposespecified.

3. The combination of the longitiulinallygrooved or channeled piston-rodwith a beveled spring-bolt, g, for the purpose described.

4. The combination, substantially as described, of the internal packingz, and perforated ring or Washer e', with the cylinder and piston-rod.

5. The combination of the cylinder and jacket o with the screws Z Z',nuts a, shaft p, and Worms q q', all arranged and operatingsubstantially as and for the purpose described.

G. rlhe combination of the threaded Wedge s, its nut s', the headedpivot r1, boss i', and bearing-piece t, With the jacket o and crossbar uof the base, all constructed and operating substantially as and for thepurpose set forth.

7. The stand or tripod X, consisting of legs o, n, and a', tubularcross-bar u, and bindingscrew y, all constructed and combinedsubstantially in the nianner described.

RGBERT BRYDON.

J. S. DAVIDSON. THGS. A. VARRINGTON.

Witnesses to the signatures of ROBERT BRY-

